passmore



wM. H. PAssMoRE, oFwYNEi. MAINE.

l TEMPEam-FURNAG.

To all 'whom t may concern.'

Be it known that I, WILLIAM I-I. PASS- MORE, of Wayne, in the county ofKennebec and State of Maine, have made a new and useful improvement inthe manner of constructing furnaces for `heating scythes and otherarticles made of steel or of iron and steel combined preparatory totheir being plunged in water or other hardening liquor for the purposeof hardening them; and I do hereby declare that the following is a fulland exact description thereof.

For the purpose of heating scythes, and other articles of a likecharacter up to the proper degreefor hardening, the general practiceheretofore has been to take them in their cold state and to pass themover the fire in a heating furnace constructed for that purpose, takingcare to heat them as equally as possible in every part; but as scythes,swords, and other articles having a cutting edge, are unequal inthickness, their thinner parts are the most quickly heated, and areliable to be injured from this cause before their backs or thicker partsare sufficiently heated for hardening. To guard against this result, ithas been necessary to heat them slowly, which is necessarily attendedwith much loss of time, while after all, the evil is but partiallycorrected. In my improved heat-ing furnace I employ a case, or oven ofcast iron for the purpose of heating the scythes or other articlespreviously to their being passed over the fire in the ordinary heatingfurnace, and in this case or oven I bring them t0 such a degree of heatas will enable me to complete the heating in the ordinary furnace withgreat rapidity. As the preparing oven contains a considerable numberwhich are successively placed within it, they have ample time to allowtheir thicker and thinner parts to be brought up to the same degree ofheat. In the accompanying drawings, Figure 1 is a perspectiverepresentation of the heating furnace which has been heretofore usedwith the exception of the brick arch by which its top has been inclosed.Fig. 2 is the cast iron case or oven which I place above the furnace'shown in Fig. l; when so placed, the bottom of said oven forms the top,or cover, of the heating furnace and will, of course, become highlyheated by the re within said furnace.

The case or preparing oven, I inclose by means of a brick arch exceptingat its fore end or mouth; this brick arch is partly` shown in Fig. 3which is a vertical longitudinal section through the middle of the wholeapparatus;

In Fig. 1, A is an opening through which the articles to be finallyheated for the purpose of being hardened, are to be passed.

B is the fire-chamber in the fore part of this furnace and C representsa blow hole through' which the blast is to be introduced to the fire.

D is a damper which is used to regulate the opening into the chimney Ewhich opening is inclosed by the brick arch.

F F Figs. 2 and 3 is the castl iron case or oven the bottom F of whichvreaches from side to sidev and from end to end of the fire chamber B Bof Fig. l. In Fig. 2 I have left out, or shown as cut away a part of thefore side of the cast iron case for the purpose of exhibiting thesupports or racks which I use to sustain the articles that are to beheated within it; these are seen at a. and b and should be so formedasto\ adapt them to the particular articles that are to be heated withinthem; those represented are such as. I have used .for scythes.

The iron case or oven F will of course have its bottom F highly heatedby means of the fire in the fire chamber, and this heat will becommunicated to the other parts thereof and the scythes or otherarticles may be readily brought to a red heat preparatory to their beingpassed through the opening A for their final heating. I sometimes coverthe bottom of the oven F with fine charcoal which will have the effectof increasing the heat and also of equalizing it.

In using this apparatus after bringing it up to the proper degree ofheat, I place a number of scythes or other artcles say from` eight, toeighteen, on the racks within it, the number being governed by the heatof the oven. When I remove one for the purpose of final heating, Ireplace it by one that is cold and the series is thus kept up. Thatwhich I remove I pass inF at the opening A where it quickly acquires theheat necessary for hardening. By this procedure I save full one half ofthe time that was required for heating under the old plan, and producemuch better work. From 4 to 5 dozen was formerly a very good hours work;with the same blast and expenditure of fuel I now harden full twice thenumber.

Having thus fully described the conformed and combined with the furnacesubstruetion of my "improved furnace for heatf'l stantially in themanner and for the pur- 10 g1g cyttlles nf othelrl articles to Il )ehr4pose set forth. vene W at c aim t eren as new an el 5 sire to secure byLetters Patent is- Y WM H PASSMORE The combining of the preparing case,or Witnesses: oven, with the heating furnace heretofore. JosIAH F.TAYLOR, employed, the saidA preparingv oven l being Y GEORGEH. WILLIAMS.

